Custom Freelance site (similar to elance/guru)

Hello, We are looking for a website similar to elance/[login to view URL], except for a different industry (for example, homebuilders, plumbers, electricians, etc). Users would post details for work, our network of service providers can view the details (budget, start date, and so on) and elect to bid on the project. Providers pay a fee to place a bid. We would also like an escrow system built in, and a feedback system (that can only be accessed if the escrow system was used). Also, if you have some sort of collaboration built in (chat/video conferencing) it would be a big positive. Obviously that is a very high level description, dozens of more features would be required, but if you already developed a similar site, you would know that. Please be prepared to send links/produce proof that you have recently developed similar using PHP or Ruby. Thanks, Mike.